DataSet D108015

\[\mathrm{He}^{2+} + \mathrm{H} \; 1s \rightarrow \mathrm{He}^{2+} + \mathrm{H} \; n=2\]


Process HEX: Excitation
Data type cross section | uploaded on 2023-02-08
Comment Fit function taken from p84. Error: E<0.5keV/u -> 100%, 0.5keV/u<E<4keV/u -> 40%, 4keV/u<E<200keV/u -> 20%, E<200keV/u -> 10%

Methodsemi-empirical
FrameTarget
Columns
  1. E /eV u-1
  2. sigma /cm2
Ref
DataDownload (data from fit)

Fitted Data

Fit Function
Details
\[\sigma_{ex}^{1\rightarrow 2}(E)=10^{-16}A_1 \Bigg[\frac{e^{-\frac{A_2}{E}}\ln(1+A_3E)}{E} + \frac{A_4e^{-A_5E}}{E^{A_6}} + \frac{A_7e^{-\frac{A_8}{E}}}{1+A_9E^{A_{10}}}\Bigg]\]
Python
def h_hex_janev_12(E, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10):
    """
    This function calculates proton impact excitation cross sections (in cm2) of 
    H n=1 to n=2 and He+2 impact excitation of H n=1 to n=2,3,4.
    param E: requested impact energy in keV/u
    type E: float, np.ndarray
    param Ai: fit coefficient 
    type Ai: float
    """
    sigma = 1e-16 * A1 * (np.exp(-A2/E) * np.log(1 + A3*E) / E + A4*np.exp(-A5*E)/E**A6 + 
                           A7*np.exp(-A8/E)/(1+A9*E**A10))
    return sigma
Fit Precision1.8 %
Fit Coefficients
A1
 1.777e+02
A2
 6.451e+01
A3
 1.081e-01
A4
 2.140e-04
A5
 7.336e-01
A6
-2.977e+00
A7
 7.560e-02
A8
 1.900e+01
A9
 2.435e-03
A10
 3.409e+00
x-range –